Mooring Buoy with galvanized chain and concrete reinforced block. The block is 36" L 26" W 9" H with a 4 inch PVC hole so it can be setup so you can inspect and change the chain without the need of a diver. The mooring buoy is manufactured with 3" diameter H.D.P.E. pipe running through the buoy, which allows 3/8″ - 3/4″ chain to run straight through the buoy for direct attachment.